Precision circle center finder and multifunctional construction trade tool

Abstract

A measuring instrument is described for application to the end of a circular member, such as a pipe, to locate the precise center of such circular member, and project it to a distant surface.

1. An instrument for determining the precise center of a circular member and projecting that determined center to a distant surface comprising:
 a cross shaped body with four arms projecting outwardly from a center hole slots formed in each of said arms and extending outwardly at right angles to one another from said center hole; 
 clip attachments movably mounted in said slots; 
 means to temporarily secure said clip attachment at precise positions within said slots; 
 means to temporarily attach said clip attachments to the peripheral end of said circular member; 
 means for projecting said center hole to a distant surface. 
 
   
   
     2. The instrument of  claim 1 , wherein said means for projecting comprises a plumb line. 
   
   
     3. The instrument of  claim 1  wherein said means for projecting comprises a laser pointer. 
   
   
     4. The instrument of  claim 1 , which includes a spirit level mounted on one or more of said arms. 
   
   
     5. The instrument of  claim 1 , wherein the said cross shaped body is formed of a material which is rigid but sufficiently flexible to fit around the curvature of said circular member. 
   
   
     6. The instrument of  claim 1 , wherein said circular member is a pipe. 
   
   
     7. The instrument  claim 1 , wherein said circular member is a pipe. 
   
   
     8. An apparatus for determining the center of a circular member and projecting that determined center to a distant surface comprising:
 a body defining a center hole, said body having four arms projecting outwardly from said center hole with adjacent arms extending outwardly at right angles relative to each other, 
 wherein each arm defines a slot beginning at a predefined distance from said center hole with each slot extending outwardly from said center hole and running along its respective arm with adjacent slots extending outwardly at right angles relative to each other; 
 a position marker movably associated with each slot wherein said position marker is configured to be secured at selected positions along its respective slot; 
 a securing-mechanism associated with each position marker and configured to temporarily associate each respective position marker with the peripheral end of said circular member thereby placing said center hole in substantial alignment with the center of said circular member thereby defining a determined center; and 
 wherein said body is configured to receive a mechanism for projecting the determined center to a distant service. 
 
   
   
     9. The instrument of  claim 8 , wherein said position marker comprises a clip attachment. 
   
   
     10. The instrument of  claim 8 , wherein the said body is formed of a material which is rigid but sufficiently flexible to fit around the curvature of said circular member. 
   
   
     11. The instrument of  claim 8 , wherein said circular member is a pipe. 
   
   
     12. The instrument of  claim 8 , wherein each arm comprises a series of distant markers extending from said center hole and along said slot with each distant marker defining a precise distance from said center hole. 
   
   
     13. The instrument of  claim 12 , wherein said distant markers comprise a plurality of holes positioned along said arm and in alignment with said center hole with each hole having a predefined distance from said center hole. 
   
   
     14. An multifunctional instrument for performing a plurality of geometric functions including squaring functions and determining the center of a circle, said instrument comprising:
 a cross shaped body with four arms projecting outwardly at right angles from a center hole so that the right angle defined by any two adjacent arms may be used to perform a squaring function; 
 wherein each arm defines a plurality of holes positioned along said arm and in alignment with said center hole with each hole having a predefined distance from said center hole; 
 wherein each hole defined by any one arm has a corresponding hole defined by at least one other arm; and 
 wherein said plurality of holes for any two adjacent arms extend outwardly at right angles to one another so that said plurality of holes can be used to perform a plurality of geometric functions including determining the center of a circle.